Leupold adjusto mounts.

I just started getting into a 99 I came acrossed years back. From a book I bought about 99s it turns out to be a R model from the 50's. I have a couple of question for any one that has tryed the Leupold Adjusto mounts and rings. Do they fit ok on a factory drilled 99 and have any tryed them with a Leupold Pioneer. The reason I'm asking is I found what looks like a nice setup on an online aution with a pretty low price for a scope and mount. Before I shell out the dough I thought I'd ask. Thanks